Chemistry
by mmwoods95
Summary: Kara is not a baker. Lena shows her the science of it. The both of them get their chemistry on, in more ways than one. Was gonna leave this as a one shot but then decided these two nerds deserve a little more.
1. Chapter 1

"You used a box recipe how bad could it turn out?" Lena asks.

Kara takes a moment, pondering if she should mention the seven other boxes and failed cakes lying in the pits of her apartment complexes trash chute.

"Um, well, this one should be fine," Kara says.

Lena laughs with a smirk and raised eyebrow.

"This one?"

"I followed all of the directions and honestly what could go wrong?"

Conveniently, as she finishes that sentence they both become aware of a sinewy string of smoke drifting up from the oven before caressing the smoke alarm and setting it off.

"Oh Rao-WOW! Wow… Not again." Kara catches herself.

The obnoxious ringing makes them both jump into action. Lena grabs a towel off the kitchen counter to fan the smoke away all the while trying not to laugh and Kara quickly moves to the oven, pulls it open and goes to reach in before getting pelted in the head with something soft, an oven mitt. She looks up at Lena, still fanning at the smoke, but now shaking her head before giving Kara a pointed look.

Kara chuckles nervously, "Ha… that could've been bad…"

"Mmm, I'm sure." Lena laughs.

Kara blushes and retrieves the burnt cake from the oven, mitt on, and sighs. Lena looks over at that, expression softening.

"You know as cute as your little scrunched up nose is when you get frustrated, darling, I can show you how to bake, no muss, no fuss, no _box_ needed."

"You know how to bake?" Kara asks.

"Well with Lex being so much older and busy with school and my model parents being what they were I spent a lot of my preteen years with nannies or the help or whoever Lillian could thrust me upon so she didn't have to bother. Some of my favorite memories of my childhood are of helping our chef, Julian, cook my birthday cake every year."

"Lena… That's beautiful."

Lena smiles sadly down at the towel still in her hand, picking at a fraying seam, before shaking her head and shrugging.

"It's something. Lillian never particularly cared for my birthday. To her it was always a reminder of the mistake I was."

Kara walks over and puts her hands over Lena's, stopping her fretting over the towel.

"You're anything but."

At that Lena looks up, sharing a long meaningful glance with Kara before she panics a little at the swoop in her chest and turns away bracing her hands on the counter and taking stock of the ingredients they have left. Quantifying numbers of eggs and cups of flower is easy it's science and it gives her escape from the wash of feelings that she's having and what they might mean.

"Anyway… Through my time with Julian I picked up plenty of baking how too, so why don't I show you?"

Kara a little disappointed from the brush off, immediately lightens up at the prospect of baking, with Lena!

"Yes! Yeah… Um I should have all the stuff and things. Yes, lets bake..."

Lena laughs, the tension in her shoulders rolling away

"Lets get to it then."

The two decide on something simple, a pineapple upside down cake, which, Kara is delighted to find out, is Lena's favorite cake. Lena tasks Kara with some simple things first, preheat the oven, find a suitable pan and open the cans of pineapples and maraschino cherries.

Then, they get to the "hard stuff," or rather the other easy stuff that when put into the hands of someone as kitchen inept as Kara, become hard. First Lena had Kara melt ¼ stick of butter to put in the bottom of the pan. Which after ¼ burnt and another ¼ that popped and went all over her microwave, Kara finally got a batch Lena deemed acceptable. They then poured that in the bottom of the cake pan and then got to work putting the allotted brown sugar, pineapples and cherries around the pan.

Not hard work but hard to watch, at least for Lena. Every time Kara would place a pineapple or cherry in the sugary mixture she would get a little on her fingers and then proceed to lick it off. Heart attack inducing material, especially when she would look up at Lena smiling while doing it, seemingly oblivious to the absolute heart palpitations she was causing.

The next part Lena does, Kara watching closely over her shoulder. Lena tries not to shudder at Kara's hot breath on her neck before showing her to mix the correct amounts of flour, baking powder, baking soda and salt into the dry mix bowl before moving on to prepare the wet mix of butter, brown sugar, egg, yogurt, milk, pineapple juice and vanilla extract and then carefully adding them both together.

Kara garnering some courage, from the obvious blush under Lena's always perfect bun, puts her arm around Lena's waist bracing it against the counter, casually pointing at the recipe asking about this and that, while hardly paying attention because who really could with that beautiful of a woman in between their arms? Definitely not her, but Kara knows exactly what she's doing.

It gives her a rush hearing Lena's breathing speed up, her heart racing and blood rushing all for her, all because of her. Yes, she's pretty terrible at baking, cooking, well food preparation in general, other than the sneaky eating she does throughout, but she isn't so dumb that she doesn't know what a tablespoon is or baking soda for that matter. But, if acting a little naïve gets Lena leaning into her, holding her wrist to show her what utensil to use and leaning back into her when she gets a right answer, well she'll play a fool forever.

Lena for her part isn't naïve either. Her heart soars as she begins catching on to the advances being made and she decides to push her luck. She finishes stirring, brings up the batter covered spoon to her lips, before turning to face Kara and giving it a saucy lick, she says,

"Do you want to taste?"

Kara, not anticipating a counter attack, especially not one like that, flushes; backing up, hand reaching up to adjust her glasses, stuttering.

"Yes…. Uh. Um no, I mean, well you just licked it, I mean not that I mind that your mouth was on it but wouldn't that be like me putting my mouth on your mouth sort of... Not that that would be a bad thing, putting our mouths together, ha, ha, what if I have to give you mouth to mouth someday or something? I don't know, um no I'm good…"

Lena bites her lip through the whole adorable ramble trying not to smile before giving pity to the flustered girl, pulling over the fruit covered baking pan, she says,

"Now all we have to do is pour this in, put it in the oven and wait."

Kara nods, thankful for the change in subject and does the final task of pouring the batter and delivering the pan to the oven.

"Okay, now we have 40-48 minutes 'til delicious cake," Kara beams.

The women head over the couch to watch some new shark documentary on Netflix that Kara had wanted to watch. Cool sharks for Kara, biology for Lena a win-win. They stretch out Kara sitting upright with her feet on the coffee table and Lena long ways along the couch with her feet in Kara's lap, only interrupted by Lena checking on the cake at the twenty minute mark and adding aluminum foil to the pan to prevent from browning.

They're not quite finished with the show when the timer for the oven goes off. Kara jumps up excitedly, pausing the doc, and rushing over to the kitchen followed by an amused and endeared Lena. Kara reaches for the oven mitt, making a show of putting it on, before reaching into the oven for the cake practically drooling at the smell.

"Oh, this smells so good!" Kara practically moans.

Lena cant help wish it was her Kara was talking about, but alas she laughs and says,

"You know we have to let it cool for ten minutes before we flip it over."

"Noooo, I want it now," Kara pouts.

"Well as head baker extraordinaire of this evening I'm going to have to say no. I promise it'll turn out much better if we wait."

Kara laments but concedes sulking her way back to the couch so they can finish the documentary while they wait. When it's finally over they both sigh in relief, Kara because its cake time and Lena because she no longer had to endure Kara's anxious leg and longing looks past her head to where the cake sat cooling in the kitchen.

They made their way to the kitchen, Kara grabbing a serving platter and Lena two small plates, and forks before coming together smiling at one another, shoulder to shoulder against the counter

"And now for the big reveal!" Kara says, giddy.

"Well get on with it then. My upside down cakes are out of this world, best in the universe even."

"Oh really. Well, I'll be the judge of that!"

Lena smirks, Kara oblivious to the bait she had just taken too distracted by flipping the pan over onto the platter, but Lena lets it go, deciding that tonight wasn't the night for that conversation.

"Well it looks good, but taste is key," Kara says, as she cuts two slices, hers considerably larger than Lena's.

Kara takes a bite, closing her eyes and throwing her head back at the taste. She can't even help herself, she moans, practically orgasms, because this cake is so freaking good.

"Mmmmmm, this is probably the best thing I have ever tasted ever. How are you so good at this?"

Lena clearly affected by the indecent sounds Kara just made, sets down her fork, stepping into her space and reaches up to wipe some crumbs off Kara's bottom lip.

"Simple really, It's just chemistry."

Her last syllable punctuated by a wink after pulling her thumb slowly down and off Kara's lip, bringing it up and sucking it into to her own mouth. Kara is visibly dazed, eyes trained on Lena's thumb still in her mouth. Lena smiles thumb between her teeth.

"What's a matter? Not going to finish your cake," Lena asks cheekily before turning back to her own, lip between her teeth now, trying and failing to hide her smile.

Kara is let go from her spell when their eye contact is lost but seeing Lena's little smirk spurs her on. Kara takes Lena's hand closest to her and reaches out for her hip with the other spinning her towards her and bringing her closer so she can push her against the counter.

"As delicious as it was, I think I'd rather finish you."

Lena laughs, while Kara flushes at her own forwardness. Lena brings her free hand up behind Kara's head pulling her so they're a breath apart and says,

"You weren't so sure about that mouth to mouth thing earlier."

Kara groans, head falling to Lena's shoulder at her teasing, Lena laughing as she turns her nose into Kara's hair whispering in her ear,

"Although my offer still stands if you'd like a taste."

Kara laughs, as she brings her head up smiling.

"I think I'd like that." She says before leaning in slowly, giving Lena a chance to back down from her offer.

Lena smiles softly holding her ground and then Kara kisses her, soft and sweet and better than any piece of cake in the universe. Their mouths slowly melded with one another's, pineapple and cherry mixing in with their own distinct flavors creating this mouthwatering combination that has them deepening the kiss for more. They break apart chests heaving, Lena smiles taking in the beautiful blue of Kara's eyes and wondering how a simple kiss could be that good, so she asks.

"How was that so good?"

Kara smiles, shaking her head a little as if to figure it out, then laughs to herself before replying,

"Simple really, we've got good chemistry."


	2. Chapter 2

It was early. Too early. Even having been dating for three months, with many a sleepover, Kara had not gotten used to how ungodly early of a riser Lena was. Super senses were not to her advantage when there was a lithe, trying to be quiet but failing, body shuffling around the room. Kara rolls over to face where Lena is rifling through the dresser bare back on full display. She finds the bra she's looking for before stringing it on

"That's my favorite."

Lena starts, whirling around.

"Kara, darling, I'm sorry. I didn't mean to wake you."

"S'okay. It was getting a little cold over here without you."

Lena smiles, full and bright, before turning back around to finish putting on her outfit for today. Kara is awake now. There is just something about that smile, the one meant just for her that breathes life into her in a way she has only ever felt from this earths yellow sun. Which is fitting, Kara thinks to herself, because she can't imagine her world revolving around anyone else this way. Lena walks over, dressed and perfectly poised as usually and sits on the bed next to Kara.

"I'm sure I could fix that."

"Mmm, could you?"

Lena leans in pressing a chaste kiss on Kara's lips before pulling back, keeping eye contact with Kara as she brings her hand up to cup her face and rid Kara's bottom lip of her usual shade.

"Still chilly?"

"Freezing." Kara replies, before grasping at the nape of Lena's neck before pulling her back in for a much deeper mouth-to-mouth endeavor.

Lena smiles into the kiss indulging in it for a minute before pulling away, standing up and flatting her hands down her skirt.

"I have to go. And so do you."

"Or we could just stay in bed all day, keeping each other warm."

"Are you propositioning me Miss Danvers? Because I already had my workout for the morning."

Lena smirks over her shoulder as she walks to the vanity to check her face and reapply. Kara laughs, throwing the covers to the side as she gets up. Lena's eyes are trained on Kara's reflection in the mirror, enamored with the sliver of skin being shown, between thin sleep shorts and her old MIT sweatshirt, as Kara throws her hands over her head to stretch.

"Who gets up at 4:30 to work out? I'm sure we can find more reasonable times and ways for you to workout like with me right now, or on lunch or late at night with a special kind of cardio."

By now Kara has made her way behind Lena, one arm coming over her shoulder, the other around her waist and buried her face into the side of Lena's neck pressing kisses all the while keeping heated eye contact with her in the mirror.

Lena closes her eyes at the sensation, raising an eyebrow before smiling and replying.

"Now I know your propositioning me"

"Really, you don't say"

They both giggle as Lena turns in Kara's arms, cupping her face.

"We really do have to go. Catco is a lot farther from here than your place and it's not like we can fly there."

Kara's nose scrunches mouth opening to say something but Lena kisses her once more on the lips before she can and leaves the embrace to grab her blazer.

"I had a feeling we were going to be running late so I made us breakfast smoothies." Lena says over her shoulder as she heads out of the bedroom towards the kitchen.

Kara runs her hand through her hair; they really need to talk. Lena has been saying things like that since they started dating and it's never in a malicious way, more of a I know and I know that you know I know but I'm going to wait until you're ready but it's just too fun not to say stuff kind of way. But, Kara thinks, it's time. She's ready for Lena to know.

Kara breathes out a laugh, feeling a weight fall off her shoulders and she hurries to get ready pulling an outfit out of the third drawer down, her drawer. Fully dressed in her usual pants, button up and cardigan, Kara puts on her glasses and heads to the kitchen.

Lena is sitting against the counter replying to emails on her phone, work mode in full swing. There are two tumblers on the counter, teal and navy, sweating with condensation. The teal leaves a ring of water as Lena lifts it to her lips eyes still trained on her phone.

"Hey."

Lena looks up, stashing her phone in her purse and grabbing the navy tumbler and handing it to Kara.

"Hey, ready to go?" She says, already making her way toward the elevator.

"Yeah, um, but can we talk."

"Yeah, can we do it in the car though? Trevor is waiting, and I have an investors conference call in a half an hour."

Lena stops when she realizes she isn't being followed and turns around walking back toward Kara concerned at the frustrated pull of her brow.

"Kara, what's up?"

"Its just really not a conversation I want to have with you half there Lena."

Lena sets her things on the counter and then puts her hands on Kara's arms.

"I'm sorry. I'm here what is it? What's going on?"

Kara takes a deep breath before, removing her glasses and looking Lena in the eyes.

"I have something really, personal, I guess, that I need to tell you and I was gonna tell you a million times before this and I had even planned out a million big reveals and speeches and none of them felt right… I just, I woke up this morning and there you were brightening up my world like the sun giving me strength and I knew that today was the day that I needed to tell you this."

Lena's heart started pounding; this was it. Kara was going to tell her she loved her.

"I'm Supergirl."

Lena's face dropped for a second before she caught herself and smiled, but not before Kara saw. Lena opened her mouth to speak and closed it a few times, blinking trying not to be disappointed.

"What's wrong? Are you mad? Talk to me Lena, please. Tell me what you're thinking."

Lena closes her eyes, shaking her head. Of course she wasn't mad, she's known exactly who she was since Kara walked in her door shadowing good 'ol corn fed Clark Kent.

"No, I'm not mad, darling. Honestly. And don't take this the wrong way but I'm just a little disappointed that's all. I thought you were going to tell me something else."

Kara's brow furrows and

"Something else? What else could I have been talking..? Oh. OH! Big speeches, romantic sun references, oh Rao, you thought I was gonna… I mean I do I just that's… Wow. And you're disappointed that I didn't, which is good because I'd be disappointed if you weren't disappointed at this point.

"Kara… It's okay if you're not ready to say it. I just misread."

"No! I love you! I do, I really do but I want you to love me, all of me I mean and that's why I wanted to tell you before we you know got any further with us, because I really do, want to go further I mean."

Lena laughs because in her mind what Kara said is just absurd. She runs her hands up Kara's arms and around her neck and pulls her in so they're inches apart.

"Kara. You flew to my office on a bus, remember?"

Kara groans, blushing, her forehead dropping to meet Lena's. Lena laughs and continues.

"And you broke my alien detector. Oh and that one time you were getting coffee with Supergirl at like eleven at night. 'That was lucky.' I have to laugh darling because I do know how much this means to you but you are so bad at this, at least around me. I love you too. All of you, and I have for a long time. Nothing to fret about."

Kara, albeit still a little embarrassed, gets that same love struck look on her face that she had when she first met Lena and goes in to kiss her. It is light and breathy, exactly how she feels right now and the only time she can remember feeling this way was the first time she went flying.

They break apart each sporting matching grins.

"I love you"

"I love _you,_ " Kara responds, before grabbing Lena in a hug and twirling her around.

Lena laughs and allows it before spotting the time on the oven.

"We really do have to go though."

"Okay."

Kara gives her one last peck on the lips before grabbing her things. Lena slings her purse over her shoulder as well and they walk to the elevator hand in hand. Kara realizing how hungry she is takes a sip of her smoothie.

"This is so good. You're literally perfect. What's in it?"

"Bananas, strawberries, yogurt-kale-honey, some protein powder, milk, the usual smoothie stuff."

Kara stops her latest sip, sticking her tongue out and making a face.

"Kale! Lena!"

Lena rolls her eyes at the dramatics.

"You can't even taste it. It's so good for you and you act like it's kryptonite."

The elevator doors open and they step in.

"It might as well be! Honestly I think I read somewhere that Kale didn't become a thing until after kryptonite was discovered so it could all be some elaborate plan to develop a plant to kill me slowly."

"You'd have to actually eat plants for it to have any effect. Just drink your smoothie dear. I promise that I probably won't make you eat kale again until the next time that I do."

Kara scoffs as the doors close, and replies leaving Lena laughing.

"I eat plants! And also that is… absolutely the worst promise I have ever heard!"


	3. Chapter 3

"Lena? Hun?" Kara calls, backing into Lena's office, hands occupied with bags of takeout.

As she turns towards the room she notices her girlfriend asleep at her desk. A warm look takes over her face as she goes to set the takeout down on the coffee table before making her way over to the desk.

"Babe," she says softly, caressing her head in an attempt to wake her up.

She melts when the response she gets is a sweet sigh and nothing else. Maneuvering carefully she lifts Lena into her arms, lolling her girlfriends head onto her shoulder and making her way to the couch, setting her down before sitting and bringing her head onto her lap.

Kara reaches behind the couch to the hidden bin of blankets, grabbing one and draping it over her girlfriend. She then pulls out her box of pot stickers multitasking between it and responding to emails on her phone.

Soon enough she has finished her second box and run out of emails to acknowledge so she takes to running her fingers through her girlfriend's hair. As she looks down at her girlfriend Kara can't help but be overcome with love and a fondness that only comes from the utmost intimacy.

Those thoughts make her look to her purse, she makes sure Lena is still fast asleep before pulling out a small velvet box and popping it open. The ring sparkled in the low light and made Kara's chest feel warm and tight like she was being wrapped in a hug. She was going to do it, she decided. Tonight.

A few minutes later when the delicious smell of Chinese is too good for the tired Luthor to ignore, her body does a long satisfying stretch and she groans because the smell and the stretch and realizing she is in the lap of the woman she loves is just the most amazing thing to wake up to.

Slumping back to jelly she looks up and grins, "Hey."

"Hi," Kara responds.

She's too enamored by the cute, sleepy display to say more so she just leans down and presses their lips together. Lena smiles in response adding pressure before being interrupted by her own loud grumbly tummy. They both laugh too comfortable with one another to be embarrassed about rogue bodily noises anymore.

"I should probably eat," Lena says against Kara's lips.

"Mhm, you probably should," Kara responds before increasing the pressure of her lips, initiating a slow languid kiss.

Lena's stomach growls again, causing Kara to sigh and sit up. Lena just laughs sitting up and stretching her arms out, exposing a sliver of stomach. The lights of the city grace her face and Kara can't help but notice how beautiful she is, ruffled from sleep and smiling that smile that is only theirs, and she's so over come with love that any other romantic plans fly out the window as she opens her mouth.

"Marry me." She forgets to even ask it as a question.

Lena's hands drop down to her lap as she turns to Kara wide eyed.

"What?"

"Marry me." Kara says more firmly smiling this time before she fumbles again awkwardly adjusting her glasses as she reaches for her purse, trifling through it and pulling out the blue velvet box opening it as she slides off the couch to one knee.

"Golly I did this all wrong but Lena Luthor, love of my life. Marry me?"

Lena caught off guard by the proposal can't help but tear up before falling to her knees and engulfing Kara in hug. Overcome with emotion she squeezes as tight as she can tears falling down her face and ecstatic burst of laughter coming from her throat.

"Is that a yes?"

Laughing once more Lena pulls back grabbing Kara's face in her hands and saying yes before smothering her with kisses each one punctuated with another affirmation.

Kara wraps her own arms around Lena reciprocating the affection and lifting them spinning into the air. Once they calm down a bit the pull back, foreheads still pressed together just gazing into one another's eyes.

"I love you." Lena says.

Kara just smiles and leans in for another kiss. She opens her mouth to respond against Lena's lips when she's interrupted by an angry growl vibrating from Lena's stomach.

They burst out laughing as Kara drops them back to the floor, Lena blushing slightly and Kara falls just a little deeper.

"I love you too.


	4. Chapter 4

Lena slouches in her seat sending a small smile to her fiancé as she goes in on the fifteenth different kind of cake. Hand to her brow, massaging away on oncoming migraine, she gets up.

"Kara, honey, I'm gonna step out for a moment"

Kara turns to her confused before being momentarily distracted by the overzealous chefs next selection. But, that moment is enough for Lena to slip outside. Catching her breath she leans against a wall and reaches for her phone, scrolling through emails. It's the most relaxing thing she's done in weeks.

Lena is stressed. Weddings are stressful. It's not even the money, obviously, but the meticulous way she has to pick out flowers and place settings and venues, invitations, and all the other million things has her borderline. The normally meticulous woman has met her match and she feels embarrassed that it's not chemical or biological or technical. Wedding planning has eviscerated her. Wedding planning….

Her phone screen starts to blur as her vision is clouded with tears. She closes her eyes bring her hand up to cover the tears from strangers passing by. Suddenly two warm, familiar arms wrap around pulling her in to a much-needed hug.

"Hey… Babe." Kara says into Lena's neck, planting a soft kiss. "What's up?"

Lena squeezes her fiancé in return, breathing in and shuddering a breath out.

"I'm stressed." Is all she can manage to get out.

Kara pulls back a little bit, keeping one hand as an anchor on Lena's waist, and bringing the other up to wipe her tears.

"You don't say… Lena it's just cake."

Lena pulls away.

"That's not it. It's all of it. I hate this. I'm not good at it."

"Hey." Kara says, "Not good at what? I've literally never seen you be bad at anything."

Lena huffs, still avoiding eye contact with Kara.

"Well I'm bad at this. I just… I don't care about flowers or plans and you know were having pineapple upside down cake and I don't like the way the wedding planner looks at you and you have people to invite and I don't so what's the point!"

The tears have started again stronger now. Kara starts to tear up as well, now understanding.

"Hey of course you have people. You have me-"

"Kara"

"Let me finish! And you have Alex and J'onn and Eve and Eliza."

"Those are your people."

Kara caresses down Lena's arm coaxing her to turn and look at her.

"Lena those are our people. They love you just as much as me. You think I don't know about your and Alex's Whiskey tour weekends. Or the way you and J'onn talk for hours about space and technology. And come on, my mom loved you the second she met you. When I go home to visit all she asks me about is you. You, Lena Luthor.

I know we haven't talked about it yet but I never wanted there to be 'sides' at our wedding. Because our family loves us equally without 'sides' and you can ask everyone of them but you have been our family for so long already."

Lena looks down, inching back into Kara's embrace. She cracks a smile into Kara's chest, placing a kiss just above her heart.

"Eliza really talks about me that much?"

Kara laughs. "Constantly!"

The couple laughs together, eyes meeting before they share a soft kiss.

"I love you Kara Danvers."

"I love you too"

Lena takes a look at the bakery, frowning before an idea pops into her brain. She smiles slyly.

"How mad would our family be if we just eloped?"

Kara grins, pulling Lena with her out of sight of the public before taking off into the air.

Alex sits with J'onn along the bar enjoying a scotch. Suddenly her phone rings, its Kara. Answering it she listens for a moment.

"You did WHAT!"

J'onn sits smirking, holding a hand out to Alex. Alex mouths "shit" as she continues listening to the phone and begrudgingly pulls out a twenty from her wallet handing it to J'onn.


End file.
